Method for making honeycomb core doors



Dec. 23, 1952 M. G. FAUSSNER 2,622,999

METHOD FOR MAKING HONEYCOMB CORE DQORS Filed Au 2, 1947 4 Sheets-Sheet 1 @rj Z 40 IN VEN TOR.

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Dec. 23, 1952 M. G. FAUSSNER ,5

METHOD FOR MAKING HONEYCOMB CORE DOORS Filed Aug. 2, 1947 4 Sheets-Sheet 2 INVEN TOR.

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Dec. 23, 1952 M. G. FAUSSNER METHOD FOR MAKING HONEYCOMB CORE DOORS 4 Sheets-Sheet 3 Filed Aug. 2, 1947 WIN: W .|.fi%

INVENTOR. MatZ/zau Gf'awwzef,

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Dec. 23, 1952 M. e. FAUSSNER 2,622,999

" METHOD FORMAKING HONEYCOMB CORE DOORS Filed Aug. 2, 1947 4 Sheets-Sheet 4 96 @97 Hge I N VEN TOR.

ficzffkew w izeri Patented Dec. 23, 1952 UNITED STATES "PATENT ore-ice "METHQD .FOR MAKING inom'iyooivm CORE noons qvlattliew G. -Fa1issner, Marsh field, Wis., .assignor ito Roddis Plywood Corporatiom-aicorporation Application August 2, 1947,,Sc1'ialNoi765fl7'7 terial economically so that the savings realized through the use of scrap will be 'reflected inf the final cost of the finished product.

Further objects of the :inventionznot specifical- 1y mentionedhere will beiapparentifromthe detailed description and claims" which 1 follow, reference being hadztoItheaccompanying drawings in which apreferred embodiment .xifathe invention is shown by'lwayof example zandin which Fig. 1 is a plan:viewwf thecrimpingapparatus employed in the presentv invention;

Fig. Zisa cross sectionaljyiew taken substantially along the .line'2".12 of.-F.ig..1,.:1ooking in the direction of the arrows;

Fig. 3 is anelevationalzview.oft-the crimping rolls taken substantially :along' the 1 line fi -.3 of Fig. 1, looking in the'directionofthe; arrows;

Fig. 41s arfragmentary; elevational view of :the glue applicators taken substantially along .the line 44 of Fig. 1, looking :in the; direction of the arrows;

Fig. 5 is'a plan viewof a;corerstripgshowing one pattern of scoring thereon;

Fig. 6 is a plan vlewofxa coreastrip. showinga second pattern of scoringzthereon;

Fig. 7 is a diagrammatic-view illustrating the clamping device;

Fig. 8 is a; planviewof; a door framezdiagraminatically illustrating the-applicationef the core thereto.

Fig. 9 is a fragmentary plan view .pfanother pattern of core made from thicker.-stock.than the core shownin-Fig. 8;

Fig. 10. is aviewjsimilar.to.,Fig.l9, showing still another pattern madefffromlstill' thicker. "stock; and

Fig. 11 is a viewv similar toi-Figs. 9Jand1 showing still thicker'stock.

In the manufacture of veneered'doors,,. panels, and the like, it has heretofore been common practice to provide-a core oiwoodjgluedtogetherand cut to the required dimensions, and on the opposite faces of which the 'panels offinish wood veneer have been secured. :Doors of' this type are rather heavy, andfin: certaininstancesjsocalled cellular cores have been employed, toili'ghten the weight of the door.

. ofscrap material have thereforebeen lost.

.52 'In most of the prior: art; doors .of which .I .am aware, good lumber i has been .cut .toform vthe core-and as a resultof the:tlaborziand'material cost;the:costoi manufacturing the cellular doors .has'fibeen undulyzihigh. .;In.. a veneer, plant; there is accumulateda largelquantity. ofscram-veneers and other wood, .which has heretofore been burned, because the I'cost of inti i fing vthis materialhas been unduly :high. .;I lumerous .attempts,..of.which .I- ;am.:aware, haveibeenmade to utilize I this scrap :material in :theiormation of cellular core :doors; however, none of these; at- .temptsjhave been verysuccessful because the cost of rfabricating .the .door -hasbeen 3 unduly high and t the advantages 3 to 1 be gained; from the 1 use i'lhe. present invention has for its main object amethod jof utilizing such scrap material in the manufacturezoficores for. doors andthe like, this method producing-a1 core at ;a cost low enough to realize an advantage from ;;the utilization of the scrap material.

,In the preferred form, the instant invention consists -,of cutting from the scrap -materialstrips having :widths @slightly greater than. the desired thickness-ofthe core, and lengths slightly, greatverthan the desired "length of vthesctn e, with the grainof 'the strips running lengthwise. 1 strips may be scored tofacilitateebending, .Ithe amount and position of the seoringdepending upon the thickness of the stock; the. distance. be-

These tween points of glue attachment and the. degree of bending to be givento the. corepieceaas .will

presently appear. The strips are scored. on both sides and a ribbon of glue applied at a plurality of spaced-apart points on one face of each strip.

The strips sol scored andi glued areassembled together and clamped undersuitable heat and pressure to effect avcuring of (the, glue andia reasonably complete drying-out of the ,material.

.After thishasbeenaccomplishe'd, the core blank so formed-is trimmed to the required length and thickness in readiness for assembly'into'thedoor.

A door is assembledfbylaying .onesuitable faceveneer in a form and assembling thereon side rails and end stiles" which form; a f hollow rectangle. into. which the'lcore blankls expanded and assembled j in engagement with said face veneer. The length of T the core; blank is sl htly greater than the distance between the inside edges of the side rails, and the width of the blank is substantially' less than :the "lengthyof these rails. "The core {blank stretched, thereby sufficiently to enable them to fit between the side rails of the door. The amount of bending that the individual strips may be given will depend upon the thickness of those strips, the pattern of glue lines used, and the number of strips to be incorporated in the core. Generally speaking, the thinner the core stock the closer together the glue lines and the greater the bending of the individual strips. The end ones of the strips are secured to the top and bottom stiles of the door by suitable means, such as staples, and the core is thus completed in readiness for the application of the second face veneer on the opposite sides of the core rails and stiles. These face veneers are glued to the faces of the rail and stile members and to the edges of the core strips which are now bent to a serpentine configuration, forming between them cells which are completely closed by the application of the facing members. Doors constructed in this manner weigh approximately one-fourth as much as a solid door of the same dimensions and are, at the same time, sufi'iciently rugged to withstand the uses to which this type of door is ordinarily put.

Scoring of the individual strips making up the core blank may be performed in a number of ways; preferably, however, this scoring is done by a roller type machine through which the individual strips are fed transversely of the grain, the scoring elements on the rolls imparting transverse scores to the strips during passage between the rolls. Guides are provided at the two ends of the rolls; and by alternating the strips, with the first against one guide and the second against the other guide, two patterns of scores can be imparted to the strips, as will presently appear. The machine also contains glue applicators, preferably discs, by which ribbons of glue are applied to the strips at the required points.

Referring now to the drawings in more detail, particularly Figs. and 6, strips of hard wood veneer are cut from scrap material to form core elements I and 2, in which the grain runs longitudinally. These elements I and 2 have widths slightly greater than the thickness of the finished core, and lengths slightly greater than the width of the core to provide for trimming and expansion, as will presently appear. The strips I are scored on their upper face with a plurality of groups of scores 3, and scored on their lower faces with groups of scores 4 which are located midway between the scores 3, as shown in Fig. 5. Glue lines 5 are applied to the under face of the strips I, on the median lines of the scores 3, as shown.

Strips 2 are likewise provided with scores 6 on their upper faces and scores I on their lower faces, with the scores I located midway between the scores 6, as shown. Glue lines 8 are applied to the under faces of the strips in registration with the scores 6, as shown. The strips I and 2, shown in Figs. 5 and 6, are scored to form one pattern of core, other patterns being contemplated, as will presently appear.

The scoring of the strips in the pattern shown in Figs. 5 and 6 is preferably done in a machine such as is shown in Figs. 1 to 4, inclusive, although the use of other types of scoring type apparatus i contemplated within the teachings of the invention.

The apparatus shown is a roller type scoring machine through which the strips are fed transversely of the grain, the machine preferably consisting of a base II] with a main vertical riser II located substantially centrally thereof and end risers I2 and I3 at opposite ends of the machine. The central risers II at each side of the base serve as end supports for shafts I5 and I6, that carry the scoring rolls and anvils, these shafts being carried in suitable journals, not shown, mounted upon the upright members so as to permit limited adjustment vertically. Extending transversely of the machine and between the upright members are cross members I1 and I8, shown as I-beams, which serve as bearing supports, as will presently appear. Additional frame members I9 and 20 connect together the center and end posts of the machine to complete the framework thereof.

Shaft l5 carries a plurality of scoring rolls 20 and anvils 2| which are spaced along the shaft by suitable spacers 22. Shaft I6 carries similar scoring rolls 23 and anvils 24 spaced therealong by spacers 25, scoring rolls 23 being arranged to register with the anvils 2| on shaft I5 and anvils 24 to register with the scoring rolls 20 on shaft I5.

Shafts I5 and I 6 carry pinion gears 26, and shaft I6 carries a sprocket Z'Iaround which a suitable driving means such as chain 28 is threaded, this chain extending to a suitable source of power such as a motor 29.

Mounted on the framework of the machine in suitable journals and near the ends thereof are shafts 30 and 3I around which are threaded conveyor loops 32 which may be chains or belts, as desired. The upper runs of these loops 32 extend between the shafts I5 and I6 and fit between adjacent scoring rolls and anvils thereon.

A suitable driving mechanism such as a belt or chain 33 encircles a pulley on shaft I6 and a pulley on shaft 3| to drive the loops 32 in the same direction as and at the same speed as the scoring rolls on shafts I5 and I6.

Also mounted upon the framework of the machine are shafts 34 and 35 which carry pulleys around which hold-down devices such as belts 36 are threaded, these devices extending between adjacent scoring rolls 20 and 2| on shaft I5 and register with the conveyor loops 32. A suitable driving device such as belt 31 encircling pulleys on shaft I5 and shaft 35 drives the loops 36 in the same direction and at the same speed as the loops 32.

Mounted on the opposite sides of the machine at the inlet end thereof are guides 40 and M, by which the operator positions the strips on the conveyors 32. Strips I are abutted against the guide 40 and strips 2 abutted against the guide 4|, so that as these strips are carried to the left, Fig. 1, they will be engaged by the hold-down belts 36 and then carried through the scoring rolls and therebeyond by the belts 32 and 36. The score patterns, such as shown in Figs. 5 and 6, will be impressed on the strips as they pass between the rolls.

As will be seen best in Figs. 2 and 4, after the strips have been carriedthrough the roll by belts 32 and 36, they are brought into engagement with the glue applicator which preferably consists of a shaft 42 that carries a plurality of discs 43 which extend into baths of glue 44 carried in suitable containers 45. A second shaft 46 likewise journaled in the machine carries anvils 41 that register with the glue discs 43 to press the strips I and 2 firmly thereagainst. Ribbons or bands of glue 5 are thus applied to the strips I, and ribbons or bands 8 applied to strips 2, as these strips move through the machine. The widths of these glue bands is determined by the thickness of discs 43.

Located at the outlet end of the machine is a suitable assembly table 5!], the forward end 5| of which bends down beneath the upper surface of the conveyor loops 3? to pick the strips off of those loops and onto theassembly table. Located at one end of the assembly table is aguide 52 and across one side is a stop 53. The operator assembles the strips together by abutting one end of each against the stop 52, thereby alternating the glue bands in the manner shown in'Figs. 5 and 6.

Limited adjustment of the shafts l5 and I6 vertically with respect to each otherpermits setting the machine to accommodate strips 'of various thicknesses and also to vary the depth of the score pattern put on the strips. Ihis adjustment can be accomplished in a number of ways within theteachings of the invention. In the example shown-in the drawings, 'wedge blocks are used for this purpose. Wedge blocks 55 engage beam H3 and a bearing El, Fig. 3, on shaft [5, for convenience shown as a ball bearing. As shown, two blocks and bearings are used on-shaft I5, which together with the journals supporting the shaft provide for its adjustment. Wedge blocks 55, two in number, engage beam ill and bearings 58 on shaft i5 and with the journals supporting that shaft provide for adjustment thereof.

The machine is provided with suitable facing plates 59 that are attached to the framework and serve to enclose the machine and to serve as guards for the moving parts thereof.

After the required number of strips have been so assembled by the operator, the core blank so formed is removed from the machine and clamped'by suitable means such as clamps (if; shown in Fig. '7, under sufficient pressure to insure proper setting of the glue. Heat is applied to the assembly thus clamped, to facilitate drying the glue in the usual manner, this heat serving also to expel moisture from the individual strips so that they will be commercially bone dry when the glue is set.

Clamps Bil are shown diagrammatically and by way of example as any suitable clamping arrangement may be used within the teachings of the invention. If desired, a continuous machine of the type shown in my co-pending application Serial No. 754,829, filed June 16, 1947, may be used. So long as the core blank is maintained clamped long enough to set the glue at the temperature used, the requirements of the invention are fulfilled.

After the glue in the individual core blanks has thus been thoroughly set, the blanks are removed from the clamps and planed to make their upper and lower faces perfectly planar and to trim the blank down to the required thickness. The ends of the blank are trimmed to insure that each individual score strip will terminate in a plane common with the other score strips and to make the blank of the proper length. The blank thus formed is now ready for insertion in the door.

Assembly of the core into a door is accomplished as shown in Fig. 8. A face panel IE with glue applied to its upper face is laid in an assembly fixture that consists of vertically disposed guides H and 12, which register with the corners of the panel. Side rails I3 and end stiles M are next laid on top of the panel 10 and registered together and with the guides H and 12. In Fig. 8, the rails F3 are shown as single piece members having sufficient width to permit attachment of hinges and mortising of locks in the usual manner. 'In certain instances, the rails 73 may each be composed of several pieces of'woodglued together, as is frequently done in doors of this type.

A core blank 15 is laid upon-the rails. It will be noted that this blank overhangs the rails somewhat, being slightly longer than the space between the inside'edges of the rails. The blank is also much shorter thanthe rails.

The blank is stretched out tocover the space between stiles 14, this stretching shortening the straight-line length of the strips therein so that they will drop down into engagement with the upper face of panel 70 and'bet'weenrails 13. The end ones of the strips in the blank, which in the example shown happen to be of the pattern shown in Fig. 5, are secured to the stiles 'M in-any preferred manner such asby staples T6. The ends of the individualstripsi *andZ in the core blank 75 abut against the inside faces'of the rails and the edges of the strips engagethe panel it. The doorassembly'iscompleted by overlaying a second face panel, not shown, on the rails, stiles and core, this "panel havingglueon itslcwer face.

The assembly thus formed is ready for clamping to set the glue. The manner of clamping will depend upon the type of glue being used. In one instance, where an air set glue'is-used, a convenient number of doors, say six, are assembled in the guides II and I2, with suitable spacers interspersed between adjacent doors, and the sandwich so formed'clamped by suitable clamps. The clamping pressure is maintained long enough to permit theglu'e to set at ordinary room temperatures. In other instances, where a thermo-setting glue is employed, the doors may be removed from the g'uidesan'd placed in a hot plate press or clamped and the glue dried by electronic drying. The particular method used to set the glue is not of theessen-ce of the present invention. 7

The panel it and the second facing panel of the door may each be'either single thickness veneers with the grain running vertically cf the door, or, if desired, each face may be covered with two or more coatings of veneer material with the grain therein alternated and with the outer or finish surface disposed with its grain vertical. In either event, the surface members are securely glued to the facesof the door frame members it and is, and to the edges of the serpentine core strips 1 and 2 :to firmly bond these elements securely together.

The number andd'epth of scorings and the plurality of scoring patterns for each strip will depend on the thickness of the veneer being utilized and upon the distancebetween glue lines, which can be varied as desired. The amount of serpentine configurationcan also be varied as desired by controlling the number of individual strips going-into one core blank. Scoring can be eliminated entirely by proper control ofglue line spacing and number of strips in the core blank, but scoringpermits the useof fewerfstrips core and closer glue line-spacing 'for more rigidity.

The core-strips land 2, when composed of hard wood veneer of ,5 inch thickness and scored as shown in Figs. 5 and 6, may be expanded sc that the distance between points -l"! and l'B, Fig. 8, is as much as two inches. In Fig. 9, strips 8s? and 8! are scored for a-differentpattern, using strips composed of thicker material than that in strips l and 2. It will be noted that the distance between adjacent glue lines'BZ and 83 is reater than the'glue lines 5'and8, Figs. 5 and 6. In cne exampleywith strips $0 and 8| composed of 1 inch hard wood veneer and with glue lines 82 and 83 spaced'B /Z inches apart, the core blank was expanded so as to'space points 8d and 85 one and three-quarters inches apart.

In Fig. 10, core strips 90 and 9| are composed of 2 inch veneer, and glue line 92 and 83 are spaced twelve inches apart. In one example, a core blank of this pattern was expanded so that the distance between points 94 and 95 was one and one-half inches. Fig. 11 shows core strips 96 and til scored and glued the same as in Fig. but composed of T inch stock. This thicker material has been expanded to space points 98 and 99 one inch apart.

From the foregoing, it will be apparent that the score patterns and glue lines can be varied sufficiently to permit using the various thicknesses of scrap to advantage.

The roller type scoring devices illustrated and described are advantageous as an inexpensive means of applying the required score patterns to the individual pieces. If desired, and in certain instances it may be advantageous to employ either scoring devices of the punch press type or saw-toothed cutters, in lieu of the roller type herein shown, and the use of such alternate equipment is contemplated within the teachings of the invention.

Through the employment of the method and apparatus of the present invention, scraps of veneer, which heretofore have been burned, can be utilized to advantage in the formation of cellular core doors, panels, and the like. The

method makes this possible by permitting fabrication of the cores at a labor cost low enough to permit realization of the economy of using the scrap material. The door so formed is light in weight and possesses great strength and resistance to warping occasioned by changes in temperature and humidity. The fire-resistant factor, while not as high as that of a solid door, is sufficiently good to permit use of the door in a large variety of installations. Because of the lighter weight of the door ordinary hardware can be used, instead of the extra heavy hardware required with solid doors.

While I have chosen to illustrate my invention by showing and describing a preferred embodiment of it, I have done so by way of example only, as there are many modifications and adaptations which can be made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What is claimed is:

1. The method of forming cellular core veneered doors comprising the steps of cutting scraps of veneer to length and width suitable to the core to be made, scoring spaced apart groups of scores extending transversely across both sides of said strips with the groups of scores on one face of the strip disposed midway between the groups of scores on the other face of the strip, applying transversely disposed bands of glue on the median lines of each group of scores on one face of the strips, assembling said strips face-to-face with the glue bands on each strip disposed midway between the glue bands on the strips that engage that strip until a core blank of the required width is made, clamping the core blank and applyin heat to set the glue, trimming the core blank to desired length and thickness, laying up side and end rail members to frame the door, expanding said core blank to bend said strips along said scores, fitting the expanded core blank into the door frame, fastening the end ones of said strips 8 to said end rail members, and gluing veneer panels to the edges of said core strips and the faces of said frame members to complete the door.

2. The method of making cellular core veneered doors comprising the steps of, cutting strips of uniform width and length from veneer scrap, simultaneously scoring groups of transverse scores on both faces of the strips with the scores on one face disposed midway between the scores on the other face, applying transverse bands of glue on the median lines of each group of scores on one face of the strips, assembling a plurality of said strips face-to-face with the bands of glue on each strip disposed midway between the bands on the strips engaging that strip to form a core blank, clamping the blank and applying heat to set the glue, planing the faces of the blank to make them planar and parallel, and to make the thickness of the blank equal to the core thickness, trimming the ends of the blank to square it and to make it the required length, laying up side and end rail members to form a hollow rectangular door frame whose inside width is slightly less than the length of said core blank, stretching said blank laterally thereby to bend the strips into honeycomb configuration and to shorten their straight line length so that the core will fit between the side rails of said frame, registering the core with the frame, securing the end ones of said strips to the end rails of said frame, and gluing veneer panels to the edges of said strips and faces of said rails to complete the door.

3. The method of making cellular core veneered doors comprising the steps of, cutting strips of uniform width and length from veneer scrap, moving said strips sideways between scoring rolls to place groups of transverse scores on both faces of the strip with the groups on one face disposed midway between the groups on the other face, applying transverse bands of glue on the median lines of each group of scores on one face of each strip, assembling a plurality of strips face-to-face with the glue bands staggered between adjacent strips to form a core blank, clamping the core blank and applying heat thereto to set the glue and to dehydrate the strips, trimming the core blank to thickness and length, laying up door frame members, stretching the blank laterally to bend the strips along said scores into honeycomb configuration, placing the elongated core into said frame with the ends of the strips abutting against the side members of the frame, securing the core to the end members of the frame, and securin veneer panels to the opposite faces of the core and frame members.

l. The method of making cellular core veneered doors comprising the steps of, cutting strips of uniform width and length from veneer with the grain running lengthwise of the strips, scoring each strip crosswise of the grain on both faces with a plurality of groups of scores and with the groups on one face disposed midway between the groups on the other face, applying spaced apart bands of glue which are parallel to and midway between the scores comprising each group on one face of each strip, assembling a plurality of strips face-to-faoe with the glue bands of each strip disposed midway between the glue bands on adjacent strips to form a core blank, clampin said core blank and applying heat to cure the glue, trimming the blank to desired length and thickness, laying up side and end door frame members on a face veneer panel that has glue applied to its upper face to form a hollow door frame there- 9 on, stretching the core blank laterally thereby to shorten said strips by bending along said score lines, registering the elongated core blank with the frame with the ends of the strips abutting against the side members of the frame, securing the end strips of the elongated core to the end members of the frame, and attaching a second veneer facing to the upper faces of the frame members and upper edges of the core.

MATTHEW G. FAUSSNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 336,424 Norris Feb. 16, 1886 Number Number 

1. THE METHOD OF FORMING CELLULAR CORE VENEERED DOORS COMPRISING THE STEPS OF CUTTING SCRAPS OF VENEER TO LENGTH AND WIDTH SUITABLE TO THE CORE TO BE MADE, SCORING SPACED APART GROUPS OF SCORES EXTENDING TRANSVERSELY ACROSS BOTH SIDES OF SAID STRIPS WITH THE GROUPS OF SCORES ON ONE FACE OF THE STRIP DISPOSED MIDWAY BETWEEN THE GROUPS OF SCORES ON THE OTHER FACE OF THE STRIP, APPLYING TRANSVERSELY DISPOSED BANDS OF GLUE ON THE MEDIAN LINES OF EACH GROUP OF SCORES ON ONE FACE OF THE STRIPS, ASSEMBLING SAID STRIPS FACE-TO-FACE WITH THE GLUE BANDS ON EACH STRIP DISPOSED MIDWAY BETWEEN THE GLUE BANDS ON THE STRIPS THAT ENGAGE THAT STRIP UNTIL A CORE BLANK OF THE REQUIRED WIDTH IS MADE, CLAMPING THE CORE BLANK AND APPLYING HEAT TO SET THE GLUE, TRIMMING THE CORE BLANK TO DESIRED LENGTH AND THICKNESS, LYING UP SIDE AND END RAIL MEMBERS TO FRAME THE DOOR, EXPANDING SAID CORE BLANK TO BEND SAID STRIPS ALONG SAID SCORES, FITTING THE EXPANDED CORE BLANK INTO THE DOOR FRAME, FASTENING THE END ONES OF SAID STRIPS TO SAID END RAIL MEMBERS, AND GLUING VENEER PANELS TO THE EDGES OF SAID CORE STRIPS AND THE FACES OF SAID FRAME MEMBERS TO COMPLETE THE DOOR. 